The noise of a high-frequency receiver, which limits the reception of weak signals, is created for the most part in the ohmic sections of the input circuit or input filter, and in the amplifier stage downstream thereof. Depending on the detailed configuration of these components, this also applies to the shielding or grounding surfaces. Noise can be reduced to one-third by cooling to temperatures of, for example, less than 80K.
It is the object of the present invention to indicate a cooling apparatus with which the noise of a high-frequency receiver can be substantially reduced, such that the power required for cooling, and the outlay for insulating the components being cooled, are to be minimized.
According to the present invention, this object is achieved by the fact that the input circuit is thermally connected to a miniature cooler and is thermally insulated, including a cold output of the miniature cooler, from the environment.
Depending on the specific prerequisites, the input circuit can contain an input filter and/or an amplifier stage, in particular a transistor.